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Ben Carson campaign finance chairman Dean Parker submitted his resignation Thursday

The departure caps weeks of departures and in-fighting inside the team for the one-time Republican front-runner

Washington CNN  — 

The man at the center of much of Ben Carson’s campaign turmoil resigned Thursday, capping weeks of departures and in-fighting inside the team for the one-time Republican front-runner.

Carson campaign finance chairman Dean Parker submitted his resignation, the Carson campaign announced.

“Dean has been a valued member of my campaign team and a trusted friend; I appreciate and honor Dean’s tireless efforts on behalf of saving America,” Carson said in a statement. “Our significant fundraising success has been due, in large part, to Dean’s dedication and commitment to ‘We the People.’”

RELATED: Ben Carson campaign at war with itself

At least four top staffers have left the Carson campaign since December 31, among them Barry Bennett, the former campaign manager, and Doug Watts, who oversaw communications. Lisa Coen, Bennett’s deputy, also resigned her post. And in New Hampshire, five paid staffers for Carson’s super PAC all left to join Sen. Ted Cruz’s campaign.

Departing campaign staffers complained of infighting, specifically blaming Carson’s longtime friend and business adviser Armstrong Williams for operating independently of other staffers. Williams remains one of Carson’s closest advisers, though he has no official role in the campaign. Always a long-shot candidate, Carson has lost much of his support among evangelicals in Iowa to Cruz.

In an interview with CNN’s Dana Bash after Thursday’s Republican presidential debate, Carson rejected any suggestion that the staff departures indicate the campaign is in turmoil.

The state of the campaign is “better than ever,” Carson said.

The campaign has led a prolific fundraising effort, at times outpacing Republican contenders, though it spent about .70 cents for every dollar raised in during last year’s second quarter.

Politico reported Thursday on griping inside the Carson campaign over Parker’s acceptance of a $20,000 monthly fee for leading fundraising efforts and spending on consultants.

“While current allegations towards me are misrepresentations, my primary goal is to help Dr. Carson save our nation,” Parker said in a statement. “I am excited about the growing momentum behind him and look forward to even greater days ahead.”

Carson at one time was challenging Donald Trump for front-runner status, but questions about his widely praised, hardscrabble life story and a shift in the debate to foreign policy prefaced a sharp decline in Carson’s support.

That slide in the polls was punctuated on New Year’s Eve 2015, with the departure of many of his top staff.

CNN’s Nia-Malika Henderson contributed to this story